LARGE LARMOR RADIUS EFFECTS ON DENSITY PERTURBATIONS IN A MAGNETIZED PLASMA
Electrostatic perturbations are considered in a model where a plasma is situated in a homogeneous magnetic field and is subject to an equivalent gravitation force representing the magnetic inhomogeneity effects. The perturbations are strongly affected by large Larmor radius (LLR) effects when their wave length becomes comparable to the ion Larmor radius. For a dilute plasma, two time-dependent constants of the motion are found permitting a solution for the perturbations. The LLR effects are shown to "chop up" the macroscopic density and electric field perturbations into a pulse- shaped periodic pattern. The latter is repeated at every half of a gyro period and becomes strongly camped between a set of arising narrow peaks. In the real situation of a plasma confined in an inhomogeneous magnetic field, the corresponding field inhomogeneity is expected to produce additional LLR phase mixing effects. Similar results for LLR effects are likely to be obtained in denser plasmas where the electric field from the space charges affects particle dynamics. Consequently, the fine structure of a number of plasma perturbations is expected to become strongly distorted by LLR effects. Lastly: deductions in terms of normal modes having the time dependence exp(iomegat) become irrelevant in presence of LLR effects.
Bibliographic Reference: WRITE TO THE DEPARTMENT OF PLASMA PHYSICS AND FUSION RESEARCH, ROYAL INSTITUTE OF TECHNOLOGY, S-100 44 STOCKHOLM (SWEDEN), MENTIONING REPORT TRITA-PFU-86-07, 1986
Record Number: 1989126018500 / Last updated on: 1989-03-01
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